1. Field of the Invention
This invention relates to a rotary printer for an envelope making machine and more particularly to a rotary printer that includes an ink distributor blade that controls the thickness of the ink film on the anilox roll of the printer module.
2. Description of the Prior Art
Blades for distributing the film of ink on a roll are old and well known as disclosed in U.S. Pat. No. 2,655,102.
Reverse-angle doctor-blades have also been used in the past in flexo printing systems. Publications dated July 1970 and January 1972 by Pamarco, Inc. of Roselle, N.J. disclose and discuss the differences between the reverse-angle doctor-blade and the conventional doctor blade disclosed in U.S. Pat. No. 2,655,102. The reverse-angle doctor-blade is positioned relative to the anilox roll in a "shaving position" with an angle less than 90.degree. between the blade and the tangent of the roll.
Other publications have discussed the development and evaluation of the reverse-angle doctor-blade ink distribution systems for flexo presses and the problems encountered with the direction of travel of the web and other problems with the adjustment of the doctor-blade assembly.
Flexo printing stations on envelope machines have also been used with envelope machines to print a plurality of colors while making the envelope. The flexo printing stations, however, required accurate and timeconsuming adjustment of the ink fountain roll and anilox roll to obtain proper ink distribution on the type or plate cylinder. The use of a distribution blade presented substantial problems especially in obtaining access to the blade for adjustment, cleaning and replacement.
The prior art has not solved the problem of providing a flexo printing module for an envelope machine that is accessible for maintenance and provides a desired thickness of the ink film on the plate or type cylinder and simple and accurate control of the thickness of the ink film on the roll while the flexo printer is operating.